Molding apparatus



H. G. SCHAEVITZ 2,333,588

MOLDING APPARATUS Filed Dec. 13, 1940 9 f1 {91 /i a J Envcntor attorney Patented Nov. 2, 1943 -MQLD N P BAT S.-. Harry G; Schaevitz, Camden; J; anplicationineeemb raa 1940;;Se i lN 36942441, 3 Claims. (01. 18 -18) This: inventionarelatesa o molding zapparatusi nd ;mor .parti. ular1y to matri s used in m01.d+-

s, pi rret e d ne ruhberitir s- In ece t y a s,- the pr oti ew fqretrea ine recapping; worn; rubber, tires; ta provide new The.

treads therefor-has; becomeqquite :eXtQnl Ye: molds or matrices usedin: thisg;art;have usually;

been cast in two halves,eacmconstitutinga;sin-

a s-i t r n t ich'requ resr-mae inin :and,

me a i e-en ravin 1 o; p ovi e non-skid ore ornamental surface T design; $1 96 tire sizes vary; r y:- wtreadzdesi nss han e from"; time to. time; it. s-apperentz hat: ne, 7' ease in thee i mol i or. he-recaralaebuskss is subi te to o siderab e x en s-inmo t:- sa dr. epla i g ne ess ry-z re.-- matr ;es,: To verc me this .diflie lty, th s he eto or een: pr p d t r pl ei he sin le, st mat i esw -t s matrix shells to which surface;inserts ;,0f;desi dconfiguration are: applied and while this typeeof m r xers: some-a van a es; i -still doesne satisfactorilyg solve the problem chiefly for; the,-

reasons that, too ,much i time is required 5 in ;replacing-, the inserts; the cost involved, is; still 111E131? tively high, and considerable storage space; is

still required.

Theprimary object of myjnvention is topro vide an improved; tire molding matrix-whichis free from the aforementioned disadvantages; V

More particularly it is. an objecteof; my invention; to v provide: an improved tire molding, matrix suitablerespecially for. recapping and fretreading worn tiresla-nd which isvery inexpensive in cost.

Anotherlobject, of my, invention isto provide an, improved tire moldingma-trix of theflinserttype which can be readily assembled in but a few min utes even by one notskilled in the-art.v

Still ,another object of, my; invention is .to pro-,. vide an improved the molding .matrix,assetiforth above which ,readily. lends ,itself .torapidmolding of large quantities, of tires,

A further object'of my. inventionis, to provide,

an improved tire molding matrix. of,the type .set

forth which can readily be accommodated to.

p ir frr ooper t ve;ta in-ar a rixnshells e ch ot which; is provided with; a.' recess extending. cirf; cumierentiallyzaround tlfiez shell-,1 the; recesses also extending from the;mating;surfaces of the shells a distance short otthe; thickness thereof In, each off the recesses is placed:v a resilientmetal band; having a plurality of; design elements ,or, ornaments in relief thereon, the bands beingtightlyfittedin the recesses to ;conf orm snugly to the curvature thereof and-being removably secured .totheir respectiye shells by a few; screws;

With; this construction; any shell may; be; used with-any band having design elements of any de sired;con figuration aflixed thereto,- and itis only,

, .m t er.-- e m nutes -1.remo et e, scr w which, hold; the design-bearing; bands on the shells; replace the bands.;and secure thenew bandsei p ce-b he-screws. r t resofiar iam t rs,,., o r spond n y l r er he sa of ou e: 7 quired; ut he: am an s ay, be 1 sedv ana prop ate inse t; lso .Ofres li n metal andalsoprovided with; the same ornaer ta design elemen erte t een. the

ends ofthebands, Thus lo making the shells and bands more or lessinterchangeable the number of parts'lrequiredtobe stocked is greatly re, duced, as are also the initial and subsequent investments;

The-novel features that I ,considercharacteristic of myinvention are;set;forthgwith particu larity in the appended-claims, Theinvention-itself, however, both as to its organizationand method of operation, together with additional objects and advantages thereof, will best,be understood; from the T following; description of several embodiments thereof, whenzread inconnec-, tion with the accompanyingdrawing, inwhich- Figure. 1 is a central, transverse sectional ;view,- of apair ofcooperating matrices formed accord-, ing to; the .present invention,

Figure 2,.is.an elevational View. looking into one ot thematrices shown in Figure 1,

Figure isa fragmentaryview similar to Figure 2 showing the; application of; the resilient band to; a-matrix oflarger diameter,"

-u e s a. a m ntar wa m lar oe ure 1 but showing amodified form-of band and showing;-, also, the application oi thisv invention to matrices ,for. molding tires of wider treads, and

Figure 5 is an enlarged, fragmentary, sectional view of a portion of one of the matrices of Figure 1.

Referring more particularly to the drawing, wherein similar reference characters designate corresponding parts throughout, there is shown,

[sam f which preferably lie in a plane normal to the axis of the shells. Each of the shells I and 3 is provided with an annular or circumferential recess I extending transversely across the shell from the surface 5 a distance short of the thick ness of the shell and terminating in an angular shoulder 9 which extends toward the surface 5 as it recedes from the base II of the recess I, so

that the shoulder 9 overlaps the base I I.

Secured tightly to the base II of each of the recesses I by means of several circumferentially spaced screws I3 is a resilient metal band I5 the inner edge of which is angularly formed to fitsnugly under the shoulder 9, thereby insuring an accurate fit against the base II. When applying the bands I5, they are slipped under the shoulders 9 after which the screws I3 are tightened down to cause the bands to assume the curvature of'the recesses I, in each case. The bands I5 may be made of cast aluminum,for example, or of sheet steel or any other desired metal, so long as they are resilient, and can be made to conform to the curvature of the recess "I in each shell.

Removably secured to the bands I5, as by screws II, are a plurality of circumferentially spaced ornamental blocks or the like I9 which constitute projections that form corresponding indentations in the surface of the tire during the molding operation to thereby provide a non-skid or ornamental tread therefor. The blocks I9 may be of any desired configuration and are so mounted on the bands I5 that they preferably overlap the shoulders 53 somewhat when the bands I5 are applied in place. The blocks or other design elements I9 are secured to the bands I5 in advance of the latters being applied to the matrix shells I and 3. A series of such bands may, of course, be preparedin advance and kept in stock, and when a desired tire tread is to be molded, the appropriate band can be applied to the shell by the screws I3 in but a few minutes. It is obvious, therefore, that a single shell can serve as the supporting structure for an infinite number of bands with an infinite variety of design elements I9 thereon. Should a tread design become obsolete and a new one come into vogue, the blocks or design elements I9 can easily be removed from the supporting band I5 and a new set of design elements applied thereto by means of the screws I'I.

In molding tires of larger diameter, the same bands I5 may be applied to shells of larger diameter, in which case, there will be a space left between the ends of the bands. This space may be filled by a resilient insert 2|, as shown in Figure 3, the insert ZI being preferably of the same material as the band I5 and having design elements l9 thereon which match the blocks I9 of the band I5. Thus, it is not necessary to provide the bands I 5 in a number of sizes, as one or more inserts ZI may be employed to fill in the space between the ends of the band, the band ends and theends of the insert or inserts ZI, asthe case may be, being provided with male and female mating portions 23, as clearly shown in Fig. 3.

When it is desired to mold or recap a tire of a wider tread, a spacer ring 25 may be employed large quantity of matrix shells need not be stocked.

From the foregoing description, it will be apparent to those skilled in the art that I have provided an improved tire molding matrix which has many advantages over prior art matrices. Not only can tread accuracy be obtained easily with my improved matrix, but the simplicity of its design and the large variety of tire sizes to which it can be applied makes the use thereof extremely economical. Although I have shown and described. several embodiments of my invention, it will be apparent to those skilled in the art that many other forms thereof, as well as changes in those described, are possible. Accordingly, I do not wish to be limited except insofar as is made necessary by the prior art and by the spirit of the appended claims.

I claim as my invention: a

1. In tire molding apparatus, a pair of complemental, annular matrix shells for molding a tire of predetermined size, said shells each having an annular recess therein adjacent the mating surfaces thereof, a resilient band in each of said recesses removably secured to its associated shell and tightly fitted against the recess thereof to conform to the curvature of the recess, said bands being shorter than the circumferences of said recesses whereby they are normally adapted to mold tires of a size smaller than said predetermined size, a pair of resilient inserts filling in the spaces between the ends of said bands and cooperating with said bands to adapt said apparatus to mold tires of said predetermined size, said inserts being also fitted tightly against their associated recesses to conform to the curvature thereof, and a plurality of design elements removably secured to said bands and to said inserts for forming a design in said tire.

2. In tire molding apparatus, a pair of complemental, annular shells each having a plane surface normal to its axis and provided with an annular recess extending away from said surface, a pair of resilient, split bands fitted tightly one in each of said recesses, means removably securing said bands to their respective shells, and a plurality of design elements on each of said bands.

3. In tire molding apparatus, a pair of complemental, annular shells each having a plane surface normal to its axis and provided with an annular recess extending away from said surface a distance short of thethickness of the shell, a pair of resilient, split bands fitted tightly one in each of said recesses, means removably securing said bands to their respective shells, each of said bands being of the same width as its associated recess, and a plurality of design elements removably secured to each of said bands.

HARRY G. SCHAEVITZ. 

